Top panel: the gray region in the background is the PDS of KIC 11615224 and the solid black line is the global background fit to the PDS. Middle panel: l = 0, 1, 2 modes in the PDS. Bottom panel: measurement of the large frequency separation and gravity mode period spacing of star. In the bottom left panel the circles are modes corresponding to l = 0, the squares are modes corresponding to l = 2, and the triangles are modes corresponding to l = 1.